Barrel-aged beers

Whiskey loyalists, take note: Barrel-aged beer bridges the gap between suds and spirits. To create these heady quaffs, American brewers fill wooden casks—which once contained bourbon, rum or even red wine—with burly beers that can stand up to the barrel's assertive flavors. (Common candidates for aging are imperial stouts, double IPAs, Belgian tripels and barleywines.) The aging process, lasting anywhere from a couple of months to more than a year, mellows and transforms this higher-alcohol hooch, imparting soft, woody notes and nuanced hints of the containers' former contents.